The present application relates to semiconductor technology. More particularly, the present application relates to a semiconductor structure containing a plurality of tall intrinsically strained high germanium percentage silicon germanium alloy fins and a method of forming the same.
The use of non-planar semiconductor devices such as, for example, silicon fin field effect transistors (FinFETs) is the next step in the evolution of complementary metal oxide semiconductor (CMOS) devices. Silicon fin field effect transistors (FETs) can achieve higher drive currents with increasingly smaller dimensions as compared to conventional planar FETs. In order to extend these devices for multiple technology nodes such as, for example, 10 nm and beyond, there is a need to boost the performance with high-mobility channels.
In such FinFET devices, a fin containing a silicon germanium alloy is one promising channel material because of its high-carrier mobility. Future technology nodes look towards silicon germanium alloys having a high germanium content (greater than 50 atomic percent germanium) as an enabling element for performance improvements. The band structure of silicon germanium alloys becomes more germanium like for germanium contents at, and above, 85 atomic percent. High germanium percentage silicon germanium alloy fins need to be on a bulk silicon substrate or a silicon-on-insulator substrate with current CMOS technology. Further performance gains might come from straining the high germanium percentage silicon germanium alloy fins. Straining high germanium percentage silicon germanium alloy fins intrinsically, rather than the challenging approach of external strain introduction by source/drain epitaxy might lead to much higher strain in high germanium percentage silicon germanium alloy fins.